Sometimes the best direction to send your signal is straight up!
Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the range between groundwave and conventional skywave distances—usually 30–400 miles (50–650 km). It is used for military and paramilitary communications, broadcasting, especially in the tropics, and by radio amateurs. The radio waves travel near-vertically upwards into the ionosphere, where they are refracted back down and can be received within a circular region up to 650 km from the transmitter. If the frequency is too high (that is, above the critical frequency of the ionospheric F layer), refraction fails to occur and if it is too low, absorption in the ionospheric D layer may reduce the signal strength.
There is no fundamental difference between NVIS and conventional skywave propagation; the practical distinction arises solely from different desirable radiation patterns of the antennas (near vertical for NVIS, near horizontal for conventional long-range skywave propagation).
Simulation table Eznec, gain and F / B in free space and real space at a wavelength from the ground Technical specifications DOWNLOAD HERE THE of the... Read more
Description: This 10-80 Meter Multiband FEA (Field Expedient Antenna) Kit enables you to customize your Alpha Multiband HF Antenna. The kit can then b... Read more
GMRS Midland Link to Part 1 https://youtu.be/AQTQptqusfc Part 2 in the micro series on GMRS. IN this video, I will show you a couple of the rad... Read more
ANTENNA ANALYZER MetroVna Pro Touch 55/180/250 MHz The idea of creating an all-Italian version of an Antenna Analyser was born as a challenge.After co... Read more
FT8 is exploding! 1#popular HamRadio digital mode In this episode of the No Nonsense Amateur Radio Podcast, Tom, KB5RF, and I explore... Read more
In this video I show you how I setup an audio mixer for my ham radio station. I am using this mixer to monitor the audio outputs from my Elecraft K3,... Read more
FT8CALL “FT8, as we know, has dominated the airwaves for over a year now. Imagine the ability to have keyboard to keyboard ragchew, with... Read more